Brummel
67027ab0f9
Final functional M5 iteration (spec ae905de; builds on green m5.1204c171+ m5.2b724cd1whose leak-proof is resolved throughdbd76e5). 3 tasks: (1) additive adapter::fold_window (windowed sibling of fold_symbol) + chrono dev-dep + a second [[bin]] timeshard_runner declaration; (2) tests/timeshard.rs written FIRST — RED is the deterministic `env!(CARGO_BIN_EXE_ timeshard_runner) not defined` compile failure (bin absent); (3) the timeshard_runner bin → GREEN, with the spec §3 strength-ordered assertions (a) per-shard bit-exact vs single-thread windowed host fold (THE boundary-invisibility proof), (b) Σ bit-exact by construction, (c) whole-window within REL_TOL=1e-6 (derived from the recursive-summation error bound, never bit-exact — spec explicit), plus the now-deterministic leak-Σ and a journal-only friction-timing capture. Boss decisions in-plan: new bin not an arg-mode (shipped symbol-fan path byte-untouched, no regression surface); chrono dev-only (date math in the test, bin date-math-free; Invariant 1 unaffected); concrete pin EURUSD 2017_03/04/05 (recon-verified present, no gaps; data-server has no month-listing API); friction is a journal observation, no bench gate, no timing assertion (flake-free); pre-existing DESIGN.md:2358-2360 M4-drift explicitly out of scope. Milestone close + mandatory audit run after Boss-verification.